Alpha-amylase variants and polynucleotides encoding same

Abstract

The present invention relates to alpha-amylase variants. The present invention also relates to polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the variants.

The invention claimed is: 
     
       1. An alpha-amylase variant comprising a substitution at positions 133 and 176 and an insertion of H, W, HW, or WH before the N-terminal amino acid, wherein
 (a) the variant has at least 90% and less than 100% sequence identity to SEQ ID NO: 14; 
 (b) position numbers correspond to the position in the alpha-amylase of SEQ ID NO: 1; and 
 (c) the variant has alpha-amylase activity. 
 
     
     
       2. The alpha-amylase variant of  claim 1 , wherein the substitution at position 176 is with Leu. 
     
     
       3. The alpha-amylase variant of  claim 1 , wherein the insertion is an insertion of His. 
     
     
       4. The alpha-amylase variant of  claim 2 , wherein the insertion is an insertion of Trp. 
     
     
       5. The alpha-amylase variant of  claim 1 , which comprises a substitution at position 133 with Phe, Tyr or Trp. 
     
     
       6. The alpha-amylase variant of  claim 2 , which comprises a substitution at position 133 with Phe, Tyr or Trp. 
     
     
       7. The alpha-amylase variant of  claim 4 , which comprises a substitution at position 133 with Phe, Tyr or Trp. 
     
     
       8. The alpha-amylase variant of  claim 1 , which comprises an insertion of His before the N-terminal amino acid+K176L+E185P. 
     
     
       9. The alpha-amylase variant of  claim 8 , which further comprises H68W. 
     
     
       10. The alpha-amylase variant of  claim 8 , which further comprises F201Y. 
     
     
       11. The alpha-amylase variant of  claim 8 , which further comprises H316W. 
     
     
       12. The alpha-amylase variant of  claim 8 , which further comprises Q360S. 
     
     
       13. The alpha-amylase variant of  claim 8 , which further comprises R437W. 
     
     
       14. The alpha-amylase variant of  claim 1 , which comprises one of the following sets of modifications:
 an insertion of His before the N-terminal amino acid+H68W+H133Y+K176L+E185P, 
 an insertion of His before the N-terminal amino acid+H68W+K176L+E185P, 
 an insertion of His before the N-terminal amino acid+H68W+Y156W+K176L+E185P, 
 an insertion of His before the N-terminal amino acid+H68W+Y158W+K176L+E185P, 
 an insertion of His before the N-terminal amino acid+H68W+K176L+E185P+F201Y+H205Y+D207V+V209D, 
 an insertion of His before the N-terminal amino acid+H68W+K176L+E185P+F279W, 
 an insertion of His before the N-terminal amino acid+H133Y+K176L+E185P+H316W+R437W, 
 an insertion of His before the N-terminal amino acid+H133Y+K176L+E185P+Q360S+R437W, 
 an insertion of His before the N-terminal amino acid+H142W+K176L+E185P+H316W+R437W, 
 an insertion of His before the N-terminal amino acid+H142W+K176L+E185P+Q360S+R437W, 
 an insertion of His before the N-terminal amino acid+P144W+K176L+E185P, 
 an insertion of His before the N-terminal amino acid+Y156W+Y158W+K176L+E185P+H316W+R437W, 
 an insertion of His before the N-terminal amino acid+Y156W+K176L+E185P+Q360S+R437W, 
 an insertion of His before the N-terminal amino acid+Y158W+K176L+E185P+F201Y+H205Y+D207V+V209D+H316W, 
 an insertion of His before the N-terminal amino acid+K176L+E185P, 
 an insertion of His before the N-terminal amino acid+K176L+E185P+H316W+L318W+R437W, 
 an insertion of His before the N-terminal amino acid+K176L+E185P+H316W+Q360S+R437W, 
 an insertion of His before the N-terminal amino acid+K176L+E185P+H316W+R437W, 
 an insertion of His before the N-terminal amino acid+K176L+E185P+Q360S+R437W, or 
 an insertion of His-Trp before the N-terminal amino acid+K176L+E185P. 
 
     
     
       15. The alpha-amylase variant of  claim 1 , which further comprises a substitution at one or more positions 68, 71, 126, 142, 144, 156, 158, 185, 201, 205, 213, 239, 279, 316, 318, 360, 416, 437, and 450. 
     
     
       16. The alpha-amylase variant of  claim 1 , which has at least 95% and less than 100% sequence identity to SEQ ID NO: 14. 
     
     
       17. A detergent composition comprising the alpha-amylase variant of  claim 1  and a surfactant. 
     
     
       18. A method of producing liquefied starch, comprising liquefying a starch-containing material with the alpha-amylase variant of  claim 1 .